Energy irradiation apparatus

ABSTRACT

An side irradiating type laser ray irradiation apparatus for irradiating a tissue with a laser ray having a deep transmitting capability for the purpose of treating, for example, Benign Prostatic Hyperplasia, cancer or other tumors. The apparatus includes an irradiating unit for reflecting the laser ray, a transporting device for transporting the irradiating unit, and an interlocking device for changing the irradiation angle of the laser ray in correspondence with the movement so that the laser ray radiated from the moving irradiating unit always passes through the same point. Since the laser ray constantly passes through a point in a deep area of the tissue, it is capable of effectively heating only the deep lesional region.

The present application is a divisional application of application Ser.No. 09/320,630 filed on May 27, 1999 now U. S. Pat. No. 6,379,347.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an apparatus that is inserted into a lumen suchas a blood vessel, urethra or abdominal cavity to irradiate a tissuewith an energy such as a laser ray or an ultrasonic ray that is capableof reaching deep into the tissue.

2. Description of the Related Art

It is well known that an energy irradiation apparatus of a long shapethat can be inserted into the body utilizing a celom or a small incisionis useful for irradiating a lesional region to reduce or to eliminate itthrough alteration, necrosis, coagulation, cauterization or evaporationfor the treatment.

The technique in general is to irradiate directly a lesional regionlocated at a surface layer of a tissue or its proximity. There isanother technique of irradiating a tissue with a purpose of curing of alesional region located deep in the tissue, or a deep lesional region.However, in order to reduce or to eliminate a tissue of the deeplesional region, it requires a relatively strong energy, which may causea damage to the surface layer.

U.S. Pat. Nos. 5,292,320 and 5,496,308 disclose irradiation apparatusesfor curing Benign Prostatic Hyperplasia by means of a laser ray as anirradiating energy. In the irradiation apparatuses, laser rays radiatedfrom a plurality of irradiating units located at different positionsconverge on a target point in the deep lesional region to generate asufficient amount of heat to reduce or to eliminate the ailing tissue.Thus, the temperature becomes higher than those of other areas wherelaser rays are not concentrated. However, since the paths of the laserrays are fixed, the temperature of a surface layer and its proximitywhere laser rays are not overlapped becomes relatively higher than thoseof other areas where any laser rays are not transmitted. This phenomenonaffects the protection of the surface layer. Therefore, it iscircumstantially difficult to heat the deep lesional region to atemperature necessary for reducing or removing the tissue of the deeplesional region while minimizing damages to the surface layer.

Also known is the leksell gamma knife, an apparatus used for thetreatment of encephalic diseases utilizing gamma ray as a source ofirradiating energy. In the apparatus, gamma rays radiated simultaneouslyfrom a plurality of irradiating units arranged in a semisphericalpattern converge on a target point in the deep lesional region to bringa necrosis to the ailing tissue. However, the gamma rays also affecttissues existing along the paths of the rays as the rays pass through.Therefore, it is circumstantially difficult with such an apparatus toreduce or to remove the ailing tissue in the deep lesional region whileminimizing the damages to the surface layer, also.

SUMMARY OF THE INVENTION

An object of the invention is to provide an apparatus that is capable ofeffectively radiating an energy to a target region, particularly aregion located in a deep area, while easily and securely preventingdamages to a normal tissue, particularly a normal tissue in the surfacelayer.

Another object of the invention is to provide a method of treatingBenign Prostatic Hyperplasia, while easily and securely preventingdamages to a normal tissue, particularly a normal tissue in the surfacelayer.

One aspect of the invention is an energy irradiation apparatus includesan irradiating unit, a transporting device and an interlocking device.The irradiating unit radiates an energy with a deep transmittingcapability against a tissue. The transporting device transports theirradiating unit within a predetermined area. The interlocking devicechanges irradiation angle in response to transportation of theirradiating unit so that the energy radiated by the moving irradiatingunit always passes through an area which is smaller than thepredetermined area.

Another aspect of the invention is a treatment method for BenignProstatic Hyperplasia by irradiating a first area existing in a lesionalregion of prostate while moving an irradiating unit for radiating laserray with a deep transmitting capability against a tissue within a secondarea which is larger than the first area and changing irradiating angleof the laser ray in correspondence to motion of the irradiating unit.

The objects, characteristics, and advantages of this invention otherthan those set forth above will become apparent from the followingdetailed description of the preferred embodiments, which refers to theannexed drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a laser ray irradiation apparatusaccording to a first embodiment of the present invention;

FIG. 2 is a cross section of a distal end of the laser ray irradiationapparatus;

FIG. 3 is a cross section along the line III—III of FIG. 2;

FIGS. 4A and 4B are a perspective view and a side view respectively fordescribing structures of an irradiating unit and arms of the laser rayirradiation apparatus;

FIGS. 5A and 5B are drawings for describing the operating principle ofthe laser ray irradiation apparatus;

FIG. 6 is a perspective view for describing a drive unit of the laserray irradiation apparatus;

FIG. 7 is a drawing to describe the relation between the motion of theirradiating unit and the direction of the energy irradiation direction;

FIG. 8 is a cross section to describe an application of the laser rayirradiation apparatus;

FIG. 9 is a cross section of a distal end of a laser ray irradiationapparatus of a second embodiment of the present invention;

FIG. 10 is a front view of a modification according to the secondembodiment;

FIG. 11 is a cross section of a distal end of an ultrasonic irradiationapparatus of a third embodiment of the present invention;

FIG. 12 is a cross section of a distal end of a laser ray irradiationapparatus of a fourth embodiment of the present invention;

FIG. 13 is a perspective view for describing the structures of anirradiating unit and an arm of the laser ray irradiation apparatus;

FIG. 14 is a drawing to describe the relation between the motion of theirradiating unit and the direction of the energy irradiation direction;

FIG. 15 is a cross section along the line XV—XV of FIG. 12;

FIG. 16 is a perspective drawing for describing the structure of a driveunit of the laser ray irradiation apparatus;

FIG. 17 is a cross section for describing an application of the laserray irradiation apparatus;

FIG. 18 is a cross section of a distal end of a laser ray irradiationapparatus of a fifth embodiment of the present invention;

FIG. 19 is a cross section along the line XIX—XIX of FIG. 18;

FIG. 20 is a drawing for describing the structure of a drive unit of thelaser ray irradiation apparatus;

FIGS. 21A to 21D are drawings for describing the drive unit;

FIG. 22 is a cross section of a distal end of a laser ray irradiationapparatus of a sixth embodiment according to the present invention;

FIG. 23 is a font view of a modification according to the sixthembodiment of the present invention;

FIG. 24 is a cross section of a distal end of an ultrasonic irradiationapparatus of a seventh embodiment of the present invention;

FIG. 25 is a plan view of a gamma ray irradiation apparatus of an eighthembodiment of the present invention; and

FIG. 26 is a perspective view of a gamma ray irradiation apparatus of aninth embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The embodiments of this invention will be described below with referenceto the accompanying drawings.

Embodiment 1

An energy irradiation apparatus 100 shown in FIG. 1 and FIG. 2 is alateral irradiating type laser ray irradiation apparatus for irradiatinga tissue with a laser ray for the purpose of treating, for example,Benign Prostatic Hyperplasia, cancer or other tumors.

The laser ray irradiation apparatus 100 includes a body 110 having along shape, an irradiating unit 111 that radiates laser ray, and ahousing 112 that contains the irradiating unit 111 and is connected thedistal end of the body 110.

The housing 112 consists of a hard tubular body having a window 115 forlaser ray irradiation. The surface of the housing 112 is covered with acovering member 113 made of a laser ray transmitting material. Thedistal end of the housing 112 is sealed with a cap 114.

The irradiating unit 111 is connected to arms 116, 117. The arms 116,117 support the irradiating unit 111 within the housing 112 in such away as to be able to slide freely, and function as the transportationmeans for transporting it in the axial direction of the body 110. Thearms 116, 117 are connected to a drive unit 150 (interlocking device),which is arranged on the proximal end of the apparatus 100. The driveunit 150 is connected to a motor (electrical drive device) 188 to whichelectric power is supplied via a cable 189. Therefore, the tilt angle ofthe irradiating unit 111 can be changed interlocked with the axialposition of the body of the irradiating unit 111.

An optical fiber (energy transmitting member) 118 is provided inside thebody 110. A lens 119 is provided at the distal end of the optical fiber118. The lens 119 is an optical element for converging laser ray intocollimated ray. The optical fiber 118 passes through a shock absorbingdevice 181 to be connected to a laser ray generating apparatus 120,which generates laser ray, via a connector. The shock absorbing device181 that contains the optical fiber 118 forming a loop absorbs themotion and/or a load of the optical fiber 118.

The apparatus 100 further includes a removable endoscope 180. Theendoscope 180 is inserted from the proximal end toward the distal end ofthe apparatus 100. A guide light for observation by the endoscope 180 isgenerated by another light source such as He—Ne laser, with which thelaser ray generating apparatus 120 is equipped, and is transmittedthrough the optical fiber 118. Therefore, it allows the operator to,observe the surface layer of the position where it is irradiated withthe laser ray, to position the housing properly based on the observationof the endoscope, and visual confirmation of the laser irradiationposition. Since the irradiated surface can be continuously observedduring a laser irradiation operation, the irradiation condition can beeasily optimized based on the actual condition.

As shown in FIG. 3, the body 110 of the apparatus 100 is equipped withworking lumens 121, 122 into which arms 116, 117 can be inserted in sucha way as to be able to slide freely. The working lumens 121, 122 areprovided in parallel with the axis of the body 110. The body 110 isfurther equipped with a lumen 123 for the optical fiber 118 as well aslumens 124, 125 for feeding and discharging the coolant. The coolant isused for alleviating the heat generated in the housing 112 due to thelaser ray, and to cool the surface layer of the tissue that contactswith the covering member 113. The lumens 124, 125 are respectivelyconnected to feeding and discharging tubes 185 and 186 (see FIG. 1) of acoolant circulating device via an inlet connector and an outletconnector provided in the apparatus. In order to prevent the coolantfrom flow backward toward the proximal end, it is preferable that eachof the lumens 121, 122, 123, and 126 has a check valve. It is possibleto use the working lumens 121, 122 for coolant feeding and dischargingas well. Physiological saline is used as a preferable coolant, becauseany leakage of such a coolant into a tissue causes least damage. Thebody 110 also has a lumen 126 for the endoscope 180 (see FIG. 1).

As shown in FIGS. 4A and 4B, the irradiating unit 111 includes a platethat contains a flat reflecting surface 127 to reflect the laser ray aswell as connecting parts 128, 129 formed on the backside of thereflecting surface 127. The irradiating unit 111 is connected rotatablyto arms 116, 117 via the connecting parts 128, 129.

Next, transporting mechanisms and irradiating angle changing mechanismsof the irradiating unit 111 will be explained referring to FIGS. 5A, 5Band 6.

As shown in FIGS. 5A and 5B, the irradiating angle of the irradiatingunit 111 and the axial movement of the arms 116, 117 are interlocked andthey are driven by the drive unit 150. More specifically, a groove cam151 with grooves 154A, 154B, 154C and a groove cam 152, which is smallerthan the groove cam 151 and has a groove 155, are provided inside thedrive unit 150, and the rotating shaft 153 of the groove cams 151, 152is connected to the shaft of the motor 188, which is the electricaldrive unit. The arms 116, 117 are moved axially and linearly by means ofthe groove cams 151, 152.

As shown in FIG. 6, the grooves 154A, 154B, 154C and the groove 155 areoval or elliptic in shape. Extension arms 156 and 157 are engaged withone of the elliptical grooves 154A, 154B, 154C and the elliptical groove155 in a movable manner, respectively. The groove cams 151, 152 arerotated around the rotating shaft 153 by the motor 188. The rotatingshaft 153 is eccentrically situated relative to the grooves 154, 155.Thus, the extension arms 156, 157 as well as arms 116, 117 repeatlinearly reciprocating motions in accordance with the rotations of thegroove cams 151, 152. The motion range of the arm 116 and the extensionarm 156 is larger than that of the arm 117, 157. Therefore, theirradiating angle of the irradiating unit 111 becomes closer to thehorizontal direction as it comes closer to the groove cams as shown inFIG. 5A and FIG. 5B.

The extension arms 156, 157 are connected via joints 158, 159 to thearms 116, 117 respectively with pivot-like mechanisms. Therefore, thearms 116, 117 are allowed to move either upward or downward in thedrawing. As shown in FIGS. 5A and 5B, the extension arms 156, 157 areprovided with adjusters 160, 161 for adjusting their lengths.

With such a constitution, the linear motion range L1 of the connectingpart 128 of the irradiating unit 111 is longer than the linear motionrange L2 of the connecting part 129, the tilt angle of the irradiatingunit 111 varies with its position as shown in FIG. 7. In other words, asthe irradiating unit 111 moves closer to the proximal end or the drivingunit 150, the tilt angle of the irradiating unit 111 reduces, while thetilt angle of the irradiating unit 111 increases as the irradiating unitmoves closer to the distal end. Therefore, the irradiating unit 111always irradiates a target point 40 with the laser ray introduced by theoptical fiber 118 regardless of the location of the irradiating unit111. The linear motion range of the irradiating unit 111 can be adjustedby changing the lengths of the extension arms 156, 157 with the help ofthe adjusters 160, 161. Moreover, the angle range of the irradiatingunit 111 is adjustable by changing the relative lengths of the extensionarms 156, 157.

Next, specific application condition and operation of the apparatus 100will be described referring to FIG. 8.

First, the distal end of the body 110 is inserted into a celom 10,wherein the housing 112 that contains the irradiating unit 111 is madeto contact with the surface layer of the proximity of a lesional region,i.e., a target region 30. At this time, it is preferable that thelocation of the housing 112 is confirmed directly using the endoscope180.

It is preferable to adjust the lengths of the extension arms 156, 157confirming the target point is located properly based on ultrasonicimages or nuclear magnetic resonance images prior to the insertion ofthe apparatus 100 into the celom 10. The lengths of the extension arms156, 157 are adjusted using the adjusters 160, 161 as described below sothat the cross point of the laser ray, i.e., the target point 40 islocated at a desired position within the target region 30.

In order to move the location of the target point 40 perpendicular tothe axis of the body 110, engaging position of the extension arm 156 ischanged as to the grooves 154A, 154B, 154C formed on the groove cam 151.Specifically, if the target point 40 is to be moved downward in FIG. 8away from the housing 112, the groove inside the groove currentlyengaged with the extension arm 156, e.g. the groove 154C is to be used.Reciprocally, if the target point 40 is desired to be moved upward inFIG. 8 toward the housing 112, the groove outside the groove presentlyengaged with the extension arm 156, e.g. the groove 154A is to be used.

If the target point 40 is to be moved in the longitudinal direction ofthe body 110, the entire apparatus 100 is moved in the longitudinaldirection of the body 110. However, the target point 40 can be likewisemoved in the longitudinal direction of the body 110 by using theadjusters 160, 161. This is suitable for a case where the movement ofthe entire apparatus 100 is difficult for some reason. Specifically, ifthe target point 40 is to be moved toward the distal end, either theextension arm 156 is shortened by means of the adjuster 160, or theextension arm 157 is elongated by means of the adjuster 161.Reciprocally, if the target point 40 is desired to be moved toward theproximal end, either the extension arm 156 is elongated by means of theadjuster 160, or the extension arm 157 is shortened by means of theadjuster 161. If it is desired to move the target point 40 in thecircumferential direction of the body 110, the entire apparatus 100 isrotated manually.

The adjustment of the position of the target point 40 is conducted asneeded according to the methods described above in the directionperpendicular to the axis of the body 110, the longitudinal direction ofthe body 110, or in the circumferential direction of the body 110.

Next, the laser ray generating apparatus 120 and the motor 188 areactivated simultaneously. The laser ray generated is then introducedinto the optical fiber 118.

The optical fiber 118 is inserted into the apparatus 100 via the shockabsorbing device 181. The laser ray is converted into a collimated rayby means of the lens 119 provided at the distal end of the optical fiber118. After passing the lens 119, the laser ray is reflected off from thereflecting surface 127 of the irradiating unit 111 contained in thehousing 112, and radiated on the target point 40. The irradiating unit111 is reciprocated axially at frequencies of 0.1 Hz to 5 Hz, or morepreferably 1 Hz to 3 Hz while changing the irradiation angle. While thepath of the laser ray is constantly changing, it always passes throughthe target point 40.

As a result, the target point 40 and its proximity inside the tissue 20become heated and reach a desired temperature. On the other hand, laserray irradiation in any region above the target area 30 on the upper sideof FIG. 8, for example, the surface layer of the tissue 20, is short sothat the amount of heat generated is limited. Similarly, the laser rayirradiation in any region below the target area 30 on the lower side ofFIG. 8 is also short so that the amount of heat generated is alsolimited. Therefore, the surrounding areas of the target area 30 are keptat relatively low temperatures to be protected from the effects of thelaser ray. As the areas other than the target area 30 are protected fromor have least chance of being damaged, the apparatus 100 has a highlysafe characteristic for the patient. It is particularly beneficial incase when the target area 30 is located deep in the tissue as thesurface layer is protected from being damaged.

Next, the position of the target point 40 is changed to initiate anotherround of irradiation. Repeating the above sequence, the entire targetarea 30 is heated and reaches the desired temperature.

As described in the above, the apparatus can move the target point 40 inany direction, particularly directions perpendicular to the axis of thebody 110. Therefore, a uniform heating and a desired temperature can beeasily achieved regardless of the position, shape or dimension of thetarget area 30. Also, localized excessive heating or insufficientheating can be prevented as well.

The laser ray radiated from the irradiating unit 111 is preferablycollimated or convergent ray. However, divergent ray is also applicablefor the purpose.

If the laser ray radiated from the irradiating unit 111 is collimated orconvergent, the energy density at the target point 40 and its proximitycan be enhanced because of its good convergence. In other words, if theenergy density of the convergent or collimated laser ray and the energydensity of the divergent laser ray are equal at the target point 40, theenergy density in the surface layer is lower in the former than in thelatter. Therefore, the collimated or convergent laser ray can moresecurely prevent damages in the surface layer than in the case of thedivergent laser ray.

If the laser ray radiated from the irradiating unit 111 is convergent,it is preferable to be constituted in such a way that the target point40 matches with the focus point of the laser ray, i.e., the point wherethe cross sectional area of the laser ray perpendicular to the axis ofthe laser ray becomes minimum. Since the focus point of the laser raycoincides with the target point 40, the energy density of the laser raycan be further intensified at the target point 40 and its proximity.

In order to make the laser ray radiated from the irradiating unit 111convergent, an optical system is provided in the path of the laser ray.The apparatus 100 has a lens 119 located at the distal end of theoptical fiber 118. It is also possible to arrange the irradiating unit111 to function as an optical system by forming the reflecting surface127 of the irradiating unit 111 as a concave mirror.

The cross sections of the working lumens 121, 122 of the body 110 can bearbitrary selected. For example, rectangular shapes can be used as wellto accommodate the changes in the vertical position of the arms 116, 117interlocked with the tilting angle of the irradiating unit 111. Any kindof laser ray that has a capability of transmitting deep into the tissuecan be used for the purpose of this invention. It is preferable,however, that the wavelength of the laser ray is in the ranges of 750 nmto 1300 nm or 1600 nm to 1800 nm, as laser rays in those wavelengthranges indicate excellent tissue transmitting capabilities. In otherwords, as the surface layer of a tissue absorbs only a small fraction ofthe energy radiated in those cases, the laser ray is radiated moreeffectively on the target area 30 located deep in the tissue.

For example, gaseous lasers such as He—Ne laser, solid lasers such asNd—YAG, and semiconductor lasers such as GaAlAs are applicable for thelaser ray generating apparatus to generate laser rays of said wavelengthranges.

There is no restriction as to the insertion part diameter of theapparatus 100, or the outer diameter of the body 110 as long as it canbe inserted into the target celom. However, the outer diameter of thebody 110 should be preferably 2 mm to 20 mm, or more preferably 3 mm to8 mm.

The body 110 can be made of a polymer alloy containing either ofpolyolefin such as polyethylene and polypropylene, ethylene-vinylacetatecopolymer (EVA), polyvinyl chloride, polyester such as polyethyleneterephthalate and polybutylene terephthalate, polyamide, polyurethane,polystyrene, or fluorocarbon resin, or a combination thereof.

The surface of the body 110 can be covered with a lubricating coatedlayer containing a material with low friction characteristic such assilicone and fluorocarbon resin, or a hydrophilic polymer material. Assuch a coating reduces surface friction, it helps smooth insertion ofthe body 110 into the celom. As an alternative, a lubricating coatedlayer can be formed on the surface of a separately prepared perishablesheath covering the body 110. Such an arrangement can prevent thedrawback of the lubricating coating layer being peeled off due to therepeated usage.

A hydrophilic polymer material used as the lubricating coated layer ispreferably either carboxymethyl cellulose, polysaccharides, polyvinylalcohol, polyethylene oxide, sodium polyacrylate, methyl vinylether-maleic anhydride copolymer, or water soluble polyamide, and morepreferably methyl vinyl ether-maleic anhydride copolymer.

When a laser ray irradiation apparatus having a body coated withhydrophilic polymer is used, it is immersed in physiological saline as apreparation. This process provides wetness on the surface of the bodyand lubricity on the apparatus. In other words, the friction resistancebetween the tissue and the apparatus reduces if the surface layer of thebody of the apparatus contains a hydrophilic polymer material. Thisalleviates the stress of the patient and improves safety. For example,insertion and extraction of the apparatus in and out of the celom, andthe movement and rotation of the apparatus within the celom can beconducted smoothly without fail.

The housing 112 is preferably made of a material with an excellent laserray transmission capability such as quartz glass, acrylic, polystyrene,polycarbonate, polyethylene, polypropylene, vinylidene chloride, andpolyester. There is no need to form the housing 112 in its entirety outof a material with a laser ray transmission capability, so that only thewindow 115 can be made of such a material. Having the window 115 forlaser ray irradiation made of a material with a good laser raytransmission capability assures an effective irradiation of the laserray. It is also possible to form the window 115 with an opening and thecovering member 113 that covers the housing 112 with one of theabovementioned materials.

The energy transmitting material does not have to be an optical fiber,but any other member that is suitable for transmitting the laser ray,such as a rod lens. The irradiating unit does not have to be plate witha flat reflecting surface, but can also be a prism or wedge plate.

Embodiment 2

An energy irradiation apparatus 200 shown in FIG. 9 is a lateralirradiating type laser ray irradiation apparatus similar to theEmbodiment 1. Only the differences from the Embodiment 1 will bediscussed in the following, skipping points of similarities.

The laser ray irradiation apparatus 200 includes an irradiating unit211, which has a concave surface for reflecting and converging the laserray transmitted by the optical fiber 218. Therefore, the apparatus 200lacks the lens 119 of the apparatus 100 in the Embodiment 1 provided atthe distal end of the optical fiber to converge the laser ray into acollimated ray. The optical fiber 218 and an arm 217 are fixed by aconnector 237. Therefore, the optical fiber 218 and the arm 217reciprocate as one unit, so that the distal end of the optical fiber218, from which the laser ray is radiated, always maintains a constantdistance against the reflecting surface 227 and the laser ray shape isalso maintained substantially constant. Since the reciprocating motionof the optical fiber 218 is absorbed into a loop within a shockabsorbing device (refer to the shock absorbing device 181 of FIG., 1),the optical fiber 218 is in a state of rest in the proximal end sideover the shock absorbing device.

The apparatus 200 further includes a balloon 230 that expands orcontracts. The balloon 230 surrounds a housing 212 located at the distalend of a body 210. The balloon 230 is preferably made of a material withan excellent laser ray transmission capability such as polyolefin,polyester, polyamide, latex and cellulose, so that the temperatureincrease caused by energy absorbed by the balloon 230 is reduced whenthe laser ray passes through the balloon 230.

The working fluid that expands the balloon 230 is supplied by the lumens(equivalent to the lumens 124, 125 shown in FIG. 3 related to theEmbodiment 1) used for feeding and discharging the coolant. One ends ofthe lumens are respectively connected to feeding and discharging tubesof a coolant circulating device via inlet and outlet connectors providedin the apparatus 200, while the other ends are communicating with theballoon 230.

The working fluid can be any fluid as long as it is capable of expandingor contracting the balloon 230, but the coolant is preferable. It isbecause that, if the coolant is used as the working fluid, it cools thesurface layer of the tissue during laser irradiation and preventsdamages on the surface layer more securely.

If the target area is in prostate, it is preferable to maintain thetarget area temperature to about 48° C. to 100° C. and the temperaturesof normal tissues, or the areas above or below the target area, below44° C. The apparatus 200 is capable of radiating the laser ray tosatisfy such a condition.

The temperature of the coolant, or the working fluid is not limited aslong as it is capable of cooling the surface layer of the tissue. It ispreferable to be below 37° C., or more preferably to be 0° C. to 25° C.,or most preferably 0° C. to 10° C. Physiological saline is preferablyused as the working fluid because any internal leakage of such a workingfluid causes least damage. If the working fluid is also a coolant, it ispreferable to circulate the working fluid in order to increase thecooling efficiency. It is also preferable to circulate the working fluidduring the period of pre-irradiation to the completion of the laserirradiation.

It is preferable to provide at the outlet connector a pressure regulatorsuch as a pressure valve that opens to release the working fluid whenthe pressure exceeds a certain value. This makes it possible to inflatethe balloon 230 at a fixed pressure regardless of the flow volume of theworking fluid. Incidentally, a depth position of the target point can beadjusted by controlling an expansion ratio or an expansion diameter ofthe balloon 230.

It is preferable to control the temperature and the flow volume of theworking fluid in relation to the laser irradiation. Overcooling oroverheating of the surface layer can be prevented in this case.

It is preferable to provide a temperature sensor on the balloon 230 todetect the surface temperature of the tissue. This makes it possible tocool the working fluid efficiently to a necessary and sufficient degreeas the information about the surface temperature of the tissue, or thetemperature detected by the sensor can be used to control the cooling ofthe working fluid.

The balloon 230 can be formed to surround the entire circumference ofthe housing 212 except the laser ray irradiation window 215 (see FIG. 9)of the body 210 as shown in FIG. 10. In this case, an excellentstability of the apparatus 200 is achieved during the laser rayirradiation period as the window 215 of the body 210 is pressed againstthe wall of the celom, or the surface of the tissue to stabilize thedistance between the target area and the irradiating unit 211.

Next, the action of the apparatus 200 will be described.

With the balloon 230 being contracted, the distal end of the apparatus200 is inserted into the celom to be located in lesional region, or inthe proximity of the target area.

The coolant, or the working fluid, is fed into the balloon 230 by, forexample, operating the pump connected to the inlet connector, andinflates the balloon 230 to a specified size. In more detail, theworking fluid flows through the inlet connector and the feeding lumeninto the cavity of the balloon 230 to inflate the balloon 230.

As the balloon 230 inflates, the position and direction of the apparatus200 becomes fixed. This makes it possible to aim the laser rayirradiation at the target point within the target area more securely andeasily. Moreover, the pressure generated due to the expansion of theballoon 230 is applied to the deep area of the tissue through thesurface of the tissue. This causes shortening of the laser ray path fromthe irradiating unit 211 to the target point, which in turn causesreduction of energy loss, or energy absorption by the tissue so that itbecomes possible to heat the target point to achieve a desiredtemperature with a lower energy level of the laser ray. Moreover, itbecomes possible to prevent the damage of the surface layer moresecurely as the surface layer of the tissue, or the area that makescontact with the balloon 230 and its vicinity is cooled by the workingfluid.

When the working fluid is circulated, the working fluid is fed from theinlet connector and discharged through the outlet connector. Morespecifically, the working fluid fed through the inlet connector flowsinto the balloon 230 via the feeding lumen. The working fluid circulatesthrough the balloon 230 and is discharged through the outlet connectorvia the discharging lumen after circulating at least half way.

When the laser irradiation at the target area is completed, the flow ofthe working fluid through the inlet connector is stopped and only thedischarge of the working fluid through the outlet connector is executed.As the working fluid in the balloon 230 is discharged through the outletconnector via the discharging lumen, the balloon 230 contracts. The body210 is removed from the celom while the balloon is contracted.

The position and direction of the apparatus 200 is fixed more easily andsecurely as mentioned before by means of the balloon 230. Moreover, inthe apparatus 200, the surface layer of the tissue is cooled with theworking fluid in the balloon 230.

It is also possible to form a lubricating coated layer on the surface ofthe balloon 230 as in the Embodiment 1. It is also possible to provide aballoon in case of the laser ray irradiation apparatus 100 of theEmbodiment 1.

Embodiment 3

An energy irradiation apparatus 300 shown in FIG. 11 is a lateralirradiating type ultrasonic ray irradiation apparatus typically used forthe treatment of Benign Prostatic Hyperplasia and various tumor such ascancer by applying an ultrasonic ray into a tissue. Only the differencesfrom the Embodiment 1 will be discussed in the following, skippingpoints of similarities.

The ultrasonic ray irradiation apparatus 300 includes a body 310 of along shape, an irradiating unit 311 having an oscillator 331, which isan ultrasonic transducer that converts electric energy into ultrasonicray, arms 316 and 317 that support the oscillator 331, and an endoscope380.

The arms 316, 317 reciprocate the oscillator 331 in the axial directionof the body 310 as in the Embodiment 1. The arms 316 and 317 have cladstructure composed of a conductor and an insulation coating layerserving as a lead wire to connect the oscillator 331 with the powersource. More specifically, the power is supplied to the oscillator 331via sliding contacts provided at groove cams (refer to the groove cams154, 155 shown in FIG. 6). The conductors of the arms 316, 317 areelectrically insulated from the groove cams.

A frequency of the ultrasonic ray cannot be determined indiscriminatelyas it varies with the type of organ where the lesional region exists,the location, depth and range of the lesional region. However, it ispreferable to use the ultrasonic ray having the frequency in the rangeof 1 MHz to 50 MHz for the soft tissue located about 1 cm to 5 cm belowthe surface layer of the tissue.

The endoscope 380 is of an oblique viewing type using a optical fiber,is detachable from the apparatus 300, and is inserted from the proximalend of the apparatus 300. The optical fiber is capable of radiating theillumination light. Therefore, it is possible to observe the positionirradiated by the ultrasonic ray, the irradiating direction and theirradiated surface condition by means of the endoscope 380. In otherwords, irradiation to improper areas can be prevented as the target areaposition can be confirmed accurately by means of the endoscope 380.Moreover, the irradiation condition can be arbitrarily changed as theirradiated surface condition can be observed continuously during theirradiation of the ultrasonic ray.

Embodiment 4

An energy irradiation apparatus 400 shown in FIG. 12 is a lateralirradiating type laser ray irradiation apparatus typically used for thetreatment of Benign Prostatic Hyperplasia and various tumor such ascancer by applying a laser ray capable of reaching deep into a tissue.Since its overall constitution is similar to the Embodiment 1, itdescription is omitted (refer to FIG. 1).

The laser ray irradiation apparatus 400 includes a body 410 having along shape, an irradiating unit 411 that radiates laser ray, and ahousing 412 that contains the irradiating unit 411 and is connected thedistal end of the body 410. The irradiating unit 411 has a single arm416. The arm 416 supports the irradiating unit 411 within the housing412 in such a way as to be able to slide freely, and function as thetransportation means for transporting it in the axial direction of thebody 410. The irradiating unit 411 has a flat reflecting surface 427formed on one side thereof to reflect the laser ray.

The housing 412 consists of a hard tubular body having a window 415 forradiating the laser ray and is covered with a laser ray transmittingcover member 413. The inner wall of the housing 412 has a pair ofgrooves 432 formed to be used for changing the irradiating angle of theirradiating unit 411. The two groves 432 that serve as a guide for theirradiating unit 411 are located facing each other across theirradiating unit 411 and are formed non-parallel to the axial directionof the body 410, i.e., tilted against the axial direction of the body410. The distal end of the housing 412 is sealed by a cap 414.

An optical fiber (energy transmitting member) 418 is provided inside thebody 410. A lens 419 is provided at the distal end of the optical fiber418. The lens 419 is an optical element for converging laser ray intocollimated ray. The optical fiber 418 passes through a shock absorbingdevice (refer to the shock absorbing device 181 of FIG., 1) to beconnected to a laser ray generating apparatus, which generates laserray, via a connector. The shock absorbing device that contains theoptical fiber 418 forming a loop absorbs the motion and/or a load of theoptical fiber 418.

The apparatus 400 further includes a removable endoscope 480. Theendoscope 480 is inserted from the proximal end toward the distal end ofthe apparatus 400. A guide light for observation by the endoscope 480 isgenerated by another light source such as He—Ne laser, with which thelaser ray generating apparatus is equipped, and is transmitted throughthe optical fiber 418. Therefore, it allows the operator to observe thesurface layer of the position where it is irradiated with the laser ray,to position the housing properly based on the observation of theendoscope, and visual confirmation of the laser irradiation position.Since the irradiated surface can be continuously observed during a laserirradiation operation, the irradiation condition can be easily optimizedbased on the actual condition.

Next, the structures of the irradiating unit 411 and the arm 416 will bedescribed referencing FIG. 13.

Since the arm 416 forks into the left and right side within the housing412 to support the irradiating unit 411, it does not prevent the laserray from irradiating the surface of the irradiating unit 411. Theirradiating unit 411 is provided at one end thereof with a support part428 and a pair of protrusions 433 on the other end. The support part 428is provided rotatably on the arm 416 to accommodate changes of theirradiating angle of the irradiating unit 411. The protrusions 433engage with the grooves 432 provided on the inner wall of the housing412. The arm 416 is connected to the drive unit located at the apparatusbase and is connected to a motor (electrical drive device). The driveunit reciprocates the irradiating unit 411 in the axial direction of thebody. Therefore, the irradiating unit 411 changes its tilt angle as itmoves its axial position on account of the interlocking action of thearm 416 and the grooves 432.

Next, the tilting angle change of the irradiating unit 411 will bedescribed referring to FIG. 14.

The distance between the arm 416 and the non-parallel grove 432 at thepoint P2 is shorter than that at the position P1. Therefore, while thesupporting part 428 of the irradiating unit 411 travels from theposition P1 to the position P2, the protrusions 433 of the irradiatingunit 411 slide along the grooves 432 and the tilting angle of theirradiating unit 411 changes. In other words, the tilting angle of theirradiating unit 411 relative to the axis of the body reduces.Similarly, when the supporting part 428 of the irradiating unit 411travels from the position P2 to the position P3, the tilting angle ofthe irradiating unit 411 further reduces. In the meantime, the laser rayreflected off from the irradiating unit 411 converges at the positionsP1 through P3 on the target point 40 in the lesional region, or thetarget area 30.

In short, the laser ray continuously irradiates only the target point40, so that other areas of the tissue such as the surface layer areirradiated only intermittently. As a result, the target point 40 isheated by the laser ray and reaches the desired temperature. On theother hand, other areas of the tissue such as the surface layer areirradiated only for short periods and thus are heated very little. Theapparatus 400 can be applied to various lesional regions with complexshapes by designing the relation between the arm 416, which is parallelto the axial direction of the body, and the non-parallel groves 432, orthe shape of the grooves 432 appropriately. For example, the grooves 432can be curvilinear as opposed to a straight line.

As shown in FIG. 15, the body 410 of the apparatus 400 is equipped witha working lumen 421 into which the arm 416 can be inserted in such a wayas to be able to slide freely. The working lumen 421 is provided inparallel with the axis of the body 410. The body 410 is further equippedwith a lumen 422 for the optical fiber 418, a lumen 423 for theendoscope 480 as well as lumen 424, 425 for feeding and discharging thecoolant. The coolant is used for alleviating the heat generated in thehousing 412 due to the laser ray, and to cool the surface layer of thetissue that contacts with the housing 412. The lumens 424, 425 arerespectively connected to feeding and discharging tubes (refer to thetubes 185, 186 of FIG. 1) of a coolant circulating device via an inletconnector and an outlet connector provided in the apparatus. In order toprevent the coolant from flow backward toward the proximal end, it ispreferable that each of the lumens 421, 422, 423, and 426 has a checkvalve. It is possible to use the working lumens 421, 422 for coolantfeeding and discharging as well. Physiological saline is used as apreferable coolant, because any leakage of such a coolant into a tissuecauses least damage.

The drive unit 450 used to reciprocate the irradiating unit 411 includesa groove cam 451 shown in FIG. 16. The groove cam 451 has an ellipticalgroove 454. A rotating shaft 453 of the groove cam 451 is connected tothe shaft of a motor 488 and offset from the center of the groove 454.The drive unit 450 further includes a cam follower 462 provided at theproximal end of the rod 456 connected to the proximal end of the arm416. The cam follower 462 engages with the groove 454 in such a manneras it can slide freely.

The groove cam 451 is driven by the motor 488 and is rotated around therotating shaft 453. The cam follower 462 is not rotated but rather iscaused to slide along the groove 454. Since the rotating shaft 453 isoffset from the center of the groove 454, the rod 456 and the arm 416connected to the rod 456 repeat reciprocating motions, or linearmotions.

Next, the specific operating condition and action of the apparatus 400will be described referring to FIG. 17.

First, the distal end of the body 410 is inserted into the celom 10, andthe housing 412 that contains the irradiating unit 411 is caused tocontact the surface layer in a proximity of the lesional region, or thetarget area. It is preferable that the location of the housing 412 isconfirmed directly by means of the endoscope 480. The position of thetarget point 40 is adjusted by moving the entire apparatus 400 in thelongitudinal direction of the body 410. The position of the target point40 relative to the circumferential direction of the body 410 is adjustedby rotating the entire apparatus 400 manually.

Next, the laser ray generating apparatus and the motor 488 are activatedsimultaneously. The laser ray generated is then introduced into theoptical fiber 418.

The optical fiber 418 is inserted into the apparatus 400 via the shockabsorbing device. The laser ray is converted into a collimated ray bymeans of the lens 419 provided at the distal end of the optical fiber418. After passing the lens 419, the laser ray is reflected off from thereflecting surface 427 of the irradiating unit 411 contained in thehousing 412, and radiated on the target point 40. The irradiating unit411 is reciprocated axially at frequencies of 0.1 Hz to 5 Hz, or morepreferably 1 Hz to 3 Hz while changing the irradiation angle. While thepath of the laser ray is constantly changing, it always passes throughthe target point 40.

As a result, the target point 40 and its proximity inside the tissue 20become heated and reach a desired temperature. On the other hand, laserray irradiation in any region above the target area 30 on the upper sideof FIG. 17, for example, the surface layer of the tissue 20, is short sothat the amount of heat generated is limited. Similarly, the laser rayirradiation in any region below the target area 30 on the lower side ofFIG. 17 is also short so that the amount of heat generated is alsolimited. Therefore, the surrounding areas of the target area 30 are keptat relatively low temperatures to be protected from the effects of thelaser ray. As the areas other than the target area 30 are protected fromor have least chance of being damaged, the apparatus 400 has a highlysafe characteristic for the patient. It is particularly beneficial incase when the target area 30 is located deep in the tissue as thesurface layer is protected from being damaged.

Next, the position of the target point 40 is changed to initiate anotherround of irradiation. Repeating the above sequence, the entire targetarea 30 is heated and reaches the desired temperature.

As described in the above, the apparatus 400 can move the target point40 in any direction, particularly directions perpendicular to the axisof the body 410 by moving the entire body 410 manually. Therefore, auniform heating and a desired temperature can be easily achievedregardless of the position, shape or dimension of the target area 30.Also, localized excessive heating or insufficient heating can beprevented as well.

The laser ray radiated from the irradiating unit 411 is preferablycollimated or convergent ray. However, divergent ray is also applicablefor the purpose.

If the laser ray radiated from the irradiating unit 411 is collimated orconvergent, the energy density at the target point 40 and its proximitycan be enhanced because of its good convergence. In other words, if theenergy density of the convergent or collimated laser ray and the energydensity of the divergent laser ray are equal at the target point 40, theenergy density in the surface layer is lower in the former than in thelatter. Therefore, the collimated or convergent laser ray can moresecurely prevent damages in the surface layer than in the case of thedivergent laser ray.

If the laser ray radiated from the irradiating unit 411 is convergent,it is preferable to be constituted in such a way that the target point40 matches with the focus point of the laser ray, i.e., the point wherethe cross sectional area of the laser ray perpendicular to the axis ofthe laser ray becomes minimum. Since the focus point of the laser raycoincides with the target point 40, the energy density of the laser raycan be further intensified at the target point 40 and its proximity.

In order to make the laser ray radiated from the irradiating unit 411convergent, an optical system is provided in the path of the laser ray.The apparatus 400 has a lens 419 located at the distal end of theoptical fiber 418. It is also possible to arrange the irradiating unit411 to function as an optical system by forming the reflecting surface427 of the irradiating unit 411 as a concave mirror.

Any kind of laser ray that has a capability of transmitting deep intotissues can be used for the purpose of this invention. It is preferable,however, that the wavelength of the laser ray is in the ranges of 750 nmto 1300 nm or 1600 nm to 1800 nm, as laser rays in those wavelengthranges indicate excellent tissue transmitting capabilities. In otherwords, as the surface layer of a tissue absorbs only a small fraction ofthe energy radiated in those cases, the laser ray is radiated moreeffectively on the target area 30 located deep in the tissue.

For example, gaseous lasers such as He—Ne laser, solid lasers such asNd—YAG, and semiconductor lasers such as GaAlAs are applicable for thelaser ray generating apparatus to generate laser rays of said wavelengthranges.

There is no restriction as to the insertion part diameter of theapparatus 400, or the outer diameter of the body 410 as long as it canbe inserted into the target celom. However, the outer diameter of thebody 410 should be preferably 2 mm to 20 mm, or more preferably 3 mm to8 mm.

The body 410 can be made of a polymer alloy containing either ofpolyolefin such as polyethylene and polypropylene, ethylene-vinylacetatecopolymer (EVA), polyvinyl chloride, polyester such as polyethyleneterephthalate and polybutylene terephthalate, polyamide, polyurethane,polystyrene, or fluorocarbon resin, or a combination thereof.

The surface of the body 410 can be covered with a lubricating coatedlayer containing a material with low friction characteristic such assilicone and fluorocarbon resin, or a hydrophilic polymer material. Assuch a coating reduces surface friction, it helps smooth insertion ofthe body 410 into the celom. As an alternative, a lubricating coatedlayer can be formed on the surface of a separately prepared perishablesheath covering the body 410. Such an arrangement can prevent thedrawback of the lubricating coating layer being peeled off due to therepeated usage.

A hydrophilic polymer material used as the lubricating coated layer ispreferably either carboxymethyl cellulose, polysaccharides, polyvinylalcohol, polyethylene oxide, sodium polyacrylate, methyl vinylether-maleic anhydride copolymer, or water soluble polyamide, and morepreferably methyl vinyl ether-maleic anhydride copolymer.

When a laser ray irradiation apparatus having a body coated withhydrophilic polymer is used, it is immersed in physiological saline as apreparation. This process provides wetness on the surface of the bodyand lubricity on the apparatus. In other words, the friction resistancebetween the tissue and the apparatus reduces if the surface layer of thebody of the apparatus contains a hydrophilic polymer material. Thisalleviates the stress of the patient and improves safety. For example,insertion and extraction of the apparatus in and out of the celom, andthe movement and rotation of the apparatus within the celom can beconducted smoothly without fail.

The housing 412 is preferably made of a material with an excellent laserray transmission capability such as quartz glass, acrylic, polystyrene,polycarbonate, polyethylene, polypropylene, vinylidene chloride, andpolyester. There is no need to form the housing 412 in its entirety outof a material with a laser ray transmission capability, so that only thewindow 415 can be made of such a material. Having the window 415 forlaser ray irradiation made of a material with a good laser raytransmission capability assures an effective irradiation of the laserray. It is also possible to form the window 415 with an opening and thecovering member 413 that covers the housing 412 with one of theabovementioned materials.

The energy transmitting material does not have to be an optical fiber,but any other member that is suitable for transmitting the laser ray,such as a rod lens. The irradiating unit does not have to be plate witha flat reflecting surface, but can also be a prism or wedge plate.

Embodiment 5

An energy irradiation apparatus 500 shown in FIG. 18 is a lateralirradiating-type irradiation apparatus similar to the Embodiment 4. Onlythe differences from the Embodiment 4 will be discussed in thefollowing, skipping points of similarities.

The laser ray irradiation apparatus 500 includes a rail member 535, anda positioning rod 536 that moves the rail member 535 in the axialdirection of the body 510. The rail member 535 has a pair of grooves(guides) 532 that engages with a pair of protrusions (refer to theprotrusions 433 of FIG. 13) provided on an irradiating unit 511.

When the rail member 535 moves toward the proximal end, the protrusionsof the irradiating unit 511 slide along the grooves 532, the tiltingangle of the irradiating unit 511 increases, and the target point, orthe focus point of the laser ray moves toward the proximal end. As aresult, a lesional region, or target area spreading in a wide rangerelative to the axial direction of the body 510 can be heated by simplymoving the rail member 535, not the entire apparatus 500. This mechanismcan reduce excoriation or abraded wound which may be caused by themovement of the apparatus 500.

The rail member 535 has a notched area that corresponds to the path ofthe laser ray so that it does not affect the passage of the laser ray.However, if the rail member 535 is made of a laser ray transmittingmaterial such as acrylic resin and quartz, the notching is not necessaryas the laser ray passes through the rail member 535.

In comparison with FIG. 15 of the Embodiment 4, the body 510 is addedwith a lumen 526 for accommodating a positioning rod 536 and the overalllumen arrangement is changed accordingly as shown in FIG. 19.

Next, the internal structure of the drive unit 550 of the apparatus 500will be described referring to FIG. 20. In order to facilitate theunderstanding of the drive mechanism, lumens other than the workinglumen 521, positioning rods, optical fiber, endoscope, etc. are notshown here, grossly simplifying the drawing.

The drive unit 550 is provided with a rotor 551. The rotor 551 includesa shaft 553, which is connected to the shaft of a motor 588, and agroove 564 formed in the radial direction on the surface. The rotor 551is connected to one end of the rod 556 via a joint 562 having a screwmember. The joint 562 is positioned along the groove 564 and is fixed tothe rotor 551 by means of the screw member. The other end of the rod 556is connected pivotally to one end of the arm 516 via the joint 563. Theother end of the arm 516 is connected to the irradiating unit 511 viathe working lumen 521 of the body 510. The reciprocating range of theirradiating unit 511 can be adjusted by changing the rotating radius ofthe joint 562 by moving the fixing position of the joint 562. Asdescribed above, the alarm 516 is supported in the working lumen 521 ofthe body 510 of a long shape in such a way that it can slide freely. Oneend of the arm 516 is connected to the rod 556 pivotally via a joint563, while the other end is connected to the irradiating unit 511. As aresult, the arm 516 moves only in the axial direction of the body 510and does not move in the vertical direction of the drawing as shown inFIG. 21A through FIG. 21D. The arm 516 and the irradiating unit 511connected to the distal end of the arm 516 repeats a reciprocatingmotion between the position shown in FIG. 21A and the position shown inFIG. 21C. As a result, the reciprocating motion range of the irradiatingunit 511 is twice the rotating radius of the joint 562.

Next, the specific operating condition and the action of the apparatus500 will be described.

First, similar to the Embodiment 4 shown in FIG. 17, the distal end ofthe body 510 is inserted into the celom 10, and the housing 512 thatcontains the irradiating unit 511 is caused to contact the surface layerin a proximity of the lesional region, or the target area 30. It ispreferable that the location of the housing 512 is confirmed directly bymeans of the endoscope 580.

Next, the target point 40 is set at a desired location within the targetarea 30. The laser ray generating apparatus is turned on and the motor588 is turned on simultaneously. The generated laser ray is thenreflected off from the reflecting surface 527 of the reflecting unit511, and radiated at the target point 40. In the meanwhile, theirradiating unit 511 is reciprocated in the axial direction by changingthe irradiated angle. After completing the processing, the position ofthe target point 40 is changed and the laser ray is radiated. Byrepeating this cycle, the entire target area 30 can be heated and reachthe desired temperature.

More specifically, the position of the positioning rod 536 is changed,and the position of the rail member 535 is adjusted. In addition, thejoint 562 is fixed to the desired position of the groove 564. It ispreferable that these settings are completed by confirming the targetpoint based on ultrasonic images or nuclear magnetic resonance imagesprior to the insertion of the distal end of the body 510 into the celom10.

When the rail member 535 is moved toward the distal direction, thetarget point 40 moves in the distal direction. When the joint 562 ismoved toward the center of the rotor 551, the reciprocating motion rangeof the irradiating unit 511 becomes shorter and the target point 40becomes closer to the surface layer, because the surface layer coolingeffect deteriorates.

When the rail member 535 moves toward the proximal end, the target point40 moves toward the proximal end. When the joint 562 is moved in adirection away from the center of the rotor 551, the reciprocatingmotion range of the irradiating unit 511 becomes longer, and the targetpoint 40 moves toward the proximal end as well as toward the directionaway from the surface layer, or toward the deeper area of the tissue.

The position of the target point 40 relative to the circumferentialdirection of the body 510 can be adjusted by manually turning the entireapparatus 500. Other actions are the same as the Embodiment 4.

Embodiment 6

An energy irradiation apparatus 600 shown in FIG. 22 is lateralirradiating type irradiation apparatus similar to the Embodiment 4 andthe Embodiment 5. Only the differences from the Embodiment 4 and theEmbodiment 5 will be discussed in the following, skipping points ofsimilarities.

The laser ray irradiation apparatus 600 is equipped with an irradiatingunit 611 having a reflecting surface 627 of a concave shape to reflectand converge the laser ray transmitted by an optical fiber 618.Therefore, the apparatus 600 is different from the Embodiment 4 and theEmbodiment 5 in that it lacks lenses such as the lenses 419, 519provided at the distal end of the optical fiber to converge the laserray into a collimated ray. The optical fiber 618 and the arm 616 areinserted into the tube 637 and fixed to each other. Therefore, theoptical fiber 618 and the arm 616 reciprocate as one unit, so that thedistal end of the optical fiber 618, from which the laser ray isradiated, always maintains a constant distance against the reflectingsurface 627 and the laser ray shape is also maintained substantiallyconstant. Since the reciprocating motion of the optical fiber 618 isabsorbed into a loop within a shock absorbing device (refer to the shockabsorbing device 181 of FIG., 1), the optical fiber 618 is in a state ofrest in the proximal end side over the shock absorbing device.

The apparatus 600 further includes a balloon 630 that expands orcontracts. The balloon 630 surrounds a housing 612 located at the distalend of a body 610. The balloon 630 is preferably made of a material withan excellent laser ray transmission capability such as polyolefin,polyester, polyamide, latex and cellulose, so that the temperatureincrease caused by energy absorbed by the balloon 630 is reduced whenthe laser ray passes through the balloon 630.

The working fluid that expands the balloon 630 is supplied by the lumens(equivalent to the lumens 424, 425 shown in FIG. 15 related to theEmbodiment 4) used for feeding and discharging the coolant. One ends ofthe lumens are respectively connected to feeding and discharging tubesof a coolant circulating device via inlet and outlet connectors providedin the apparatus 600, while the other ends are communicating with theballoon 630.

The working fluid can be any fluid as long as it is capable of expandingor contracting the balloon 630, but the coolant is preferable. It isbecause that, if the coolant is used as the working fluid, it cools thesurface layer of the tissue during laser irradiation and preventsdamages on the surface layer more securely.

If the target area is in prostate, it is preferable to maintain thetarget area temperature to about 48° C. to 100° C. and the temperaturesof normal tissues, or the areas above or below the target area, below44° C. The apparatus 600 is capable of radiating the laser ray tosatisfy such a condition.

The temperature of the coolant, or the working fluid is not limited aslong as it is capable of cooling the surface layer of the tissue. It ispreferable to be below 37° C., or more preferably to be 0° C. to 25° C.,or most preferably 0° C. to 10° C. Physiological saline is preferablyused as the working fluid because any internal leakage of such a workingfluid causes least damage. If the working fluid is also a coolant, it ispreferable to circulate the working fluid in order to increase thecooling efficiency. It is also preferable to circulate the working fluidduring the period of pre-irradiation to the completion of the laserirradiation.

It is preferable to provide at the outlet connector a pressure regulatorsuch as a pressure valve that opens to release the working fluid whenthe pressure exceeds a certain value. This makes it possible to inflatethe balloon 630 at a fixed pressure regardless of the flow volume of theworking fluid. Incidentally, a depth position of the target point can beadjusted by controlling an expansion ratio or an expansion diameter ofthe balloon 630. It is preferable to control the temperature and theflow volume of the working fluid in relation to the laser irradiation.Overcooling or overheating of the surface layer can be prevented in thiscase.

It is preferable to provide a temperature sensor on the balloon 630 todetect the surface temperature of the tissue. This makes it possible tocool the working fluid efficiently to a necessary and sufficient degreeas the information about the surface temperature of the tissue, or thetemperature detected by the sensor can be used to control the cooling ofthe working fluid.

The balloon 630 can be formed to surround the entire circumference ofthe housing 612 except the laser ray irradiation window 615 (see FIG.22) of the body 610 as shown in FIG. 23. In this case, an excellentstability of the apparatus 600 is achieved during the laser rayirradiation period as the window 615 of the body 610 is pressed againstthe wall of the celom, or the surface of the tissue to stabilize thedistance between the target area and the irradiating unit 611.

Next, the action of the apparatus 600 will be described.

With the balloon 630 being contracted, the distal end of the apparatus600 is inserted into the celom to be located in lesional region, or inthe proximity of the target area.

The coolant, or the working, fluid, is fed into the balloon 630 by, forexample, operating the pump connected to the inlet connector, andinflates the balloon 630 to a specified size. In more detail, theworking fluid flows through the inlet connector and the feeding lumeninto the cavity of the balloon 630 to inflate the balloon 630.

As the balloon 630 inflates, the position and direction of the apparatus600 becomes fixed. This makes it possible to aim the laser rayirradiation at the target point within the target area more securely andeasily. Moreover, the pressure generated due to the expansion of theballoon 630 is applied to the deep area of the tissue through thesurface of the tissue. This causes shortening of the laser ray path fromthe irradiating unit 611 to the target point, which in turn causesreduction of energy loss, or energy absorption by the tissue so that itbecomes possible to heat the target point to achieve a desiredtemperature with a lower energy level of the laser ray. Moreover, itbecomes possible to prevent the damage of the surface layer moresecurely as the surface layer of the tissue, or the area that makescontact with the balloon 630 and its vicinity is cooled by the workingfluid.

When the working fluid is circulated, the working fluid is fed from theinlet connector and discharged through the outlet connector. Morespecifically, the working fluid fed through the inlet connector flowsinto the balloon 630 via the feeding lumen. The working fluid circulatesthrough the balloon 630 and is discharged through the outlet connectorvia the discharging lumen after circulating at least half way.

When the laser irradiation at the target area is completed, the flow ofthe working fluid through the inlet connector is stopped and only thedischarge of the working fluid through the outlet connector is executed.As the working fluid in the balloon 630 is discharged through the outletconnector via the discharging lumen, the balloon 630 contracts. The body610 is removed from the celom while the balloon is contracted.

The position and direction of the apparatus 600 is fixed more easily andsecurely as mentioned before by means of the balloon 630. Moreover, inthe apparatus 600, the surface layer of the tissue is cooled with theworking fluid in the balloon 630.

It is also possible to form a lubricating coated layer on the surface ofthe balloon 630 as in the Embodiment 4. It is also possible to provide aballoon in case of the laser ray irradiation apparatuses 400, 500 of theEmbodiments 4, 5.

Embodiment 7

An energy irradiation apparatus 700 shown in FIG. 24 is a lateralirradiating type ultrasonic ray irradiation apparatus typically used forthe treatment of Benign Prostatic Hyperplasia and various tumor such ascancer by applying an ultrasonic ray into a tissue. Only the differencesfrom the Embodiment 4 through the Embodiment 6 will be discussed in thefollowing, skipping points of similarities.

The ultrasonic ray irradiation apparatus 700 includes a body 710 of along shape, an irradiating unit 711 having an oscillator 731, which isan ultrasonic transducer that converts electric energy into ultrasonicray, arms 716 that supports the irradiating unit 711, and an ultrasonicendoscope 780. The structure and actions of a positioning rod 736 and arail member 735 that have grooves (guide) 732 and moves in the axialdirection of the body 710, and a positioning rod 736 are similar to theEmbodiment 5 and the Embodiment 6. The apparatus 700 further includes apair of lead wires 738 with an insulating coated layer to supplyelectric power to the oscillator 731. The lead wire 738 is arranged tobe wrapped around the arm 716. The housing 712 contains in the inside anultrasonic ray transmitting substance such as physiological saline.Therefore, the ultrasonic ray of the endoscope 780 and the ultrasonicray generated by the oscillator 731 are effectively transmitted to theoutside of the housing 712.

A frequency of the ultrasonic ray cannot be determined indiscriminatelyas it varies with the type of organ where the lesional region exists,the location, depth and range of the lesional region. However, it ispreferable to use the ultrasonic ray having the frequency in the rangeof 1 MHz to 50 MHz for the soft tissue located about 1 cm to 5 cm belowthe surface layer of the tissue.

The endoscope 780 is of an oblique viewing, is detachable from theapparatus 700, and is inserted from the proximal end of the apparatus700. It is possible to observe the position irradiated by the ultrasonicray irradiating unit 711, the irradiating direction and the irradiatedsurface condition by means of the endoscope 780. In other words,irradiation to improper areas can be prevented as the target areaposition can be confirmed accurately by means of the endoscope 780.Moreover, the irradiation condition can be arbitrarily changed as theirradiated surface condition can be observed continuously during theirradiation of the ultrasonic ray.

The movements of the irradiating unit in the Embodiment 4 through theEmbodiment 8 are controlled in the interlocking activities between thetransporting device (arm) and the guide (grooves) fixed during theirradiation. In other words, changes of the reciprocating movement andthe tilting angle of the irradiating unit are realized by thetransporting device consisting of a single bar-like member. Therefore,the structure of the apparatus is simple, the manufacture of theapparatus is easier, and the possibility of the apparatus' malfunctionis small.

Moreover, if an adjusting device such as the positioning rod or thejoint and groove is provided to change the guide position or themounting location of the rod, the target point position can be changedwithout moving the body. In this case, the entire target area can beheated uniformly to a desired temperature while maintaining thetemperatures of the areas other than the target area at relatively lowtemperatures. In other words, the operation is easier and the patient'sstress can be reduced.

Embodiment 8

An energy irradiation apparatus 800 shown in FIG. 25 is a gamma rayirradiation apparatus typically used for the treatment ofcerebrovascular disease and intracerebral disease such as brain tumor byapplying an ultrasonic ray into a tissue. The bodies of the energyirradiation apparatuses related to the Embodiment 1 through theEmbodiment 7 are inserted into the celom to treat the lesional region inthe neighborhood of the celom. On the other hand, the gamma rayirradiation apparatus 800 is externally disposed to treat the lesionalregion 30.

The gamma ray irradiation apparatus 800 includes an irradiating unit 811with a cobalt-60 radiation source for radiating the gamma ray, and aring-shaped rail 840 for moving the irradiating unit 811. The center ofthe rail 840 is located at a target point 40 of a target area 30, or thelesional region in the brain. Therefore, by moving the irradiating unit811 along the rail 840 while the gamma ray is radiated from theirradiating unit 811, the gamma ray constantly passes through the targetpoint 40. In other words, the gamma ray can be used to treat only thedeep lesional region while protecting other area of normal tissue intact. A linear motor can be used as the drive source of the irradiatingunit 811.

Embodiment 9

An energy irradiation apparatus 900 shown in FIG. 26 is a gamma rayirradiation apparatus similar to the Embodiment 8. only the differencesfrom the Embodiment 8 will be discussed in the following, skippingpoints of similarities.

The gamma ray irradiation apparatus 900 includes a irradiating unit 911with a cobalt-60 radiation source for radiating the gamma ray, and adrive unit 950 that is interlocked with the irradiating unit 911 via anarm 916. The irradiating unit 911 is rotated around the axis of thedrive unit 950 which is connected to a motor. Different from theEmbodiment 8, the path of gamma ray is not on a single plane butchanges. In other words, the path of the gamma rays forms a cone and thegamma ray constantly passes through the apex 40 of the cone, or a targetpoint 40 of a target area 30 in the brain. Therefore, even when anobstacle exists adjacent to the surface layer of the tissue surroundingthe lesional region 30 so that it is difficult to use the apparatus 800of the Embodiment 8, the present apparatus 900 can be easily applied. Itis suitable for treatment of disease in the abdominal region, forexample.

It is obvious that this invention is not limited to the particularembodiments shown and described above but may be variously changed andmodified by any person of ordinary skill in the art without departingfrom the technical concept of this invention.

For example, the constitution of each part can be replaced with anyconstitution that provides a similar function. Also, the features ofeach embodiment mentioned above can be combined. Specifically, theendoscopes 180, 380 used in the Embodiments 1, 3 can be used for theEmbodiment 2. The balloon 230 used in the Embodiment 2 can be used forthe Embodiments 1, 3. The ultrasonic transducer 731 used in theEmbodiment 7 is applicable in the Embodiment 4 through the Embodiment 6.The balloon 630 used in the Embodiment 6 is applicable to theEmbodiments 4, 5 and 7.

Further, the entire disclosure of Japanese Patent Application No.10-148023 filed on May 28, 1998 and Japanese Patent Application No.10-165423 filed on Jun. 12, 1998 including the specification, claims,drawings and summary is incorporated herein by reference in itsentirety.

What is claimed is:
 1. A method for treating a lesional region locateddeep in a tissue while protecting a surface layer of the tissue frombeing damaged, comprising: positioning a housing in contact with thesurface layer of the tissue; moving an irradiating unit continuously inthe housing while energy with a deep transmitting capability against thetissue radiates from the irradiating unit toward the lesional region;and controlling a reflected irradiating angle by moving the irradiatingunit so that the energy always converges toward the lesional region. 2.The method in accordance with claim 1, in which the surface layer of thetissue in contact with the housing is cooled during the energyirradiation.
 3. A method in accordance with claim 1, in which saidlesional region is a prostate.
 4. The method in accordance with claim 1,in which the energy irradiation is conducted so that the temperature inthe lesional region is 48° C. to 55° C. and the temperature in an upperor lower area of the lesional region is below 44° C.
 5. The method inaccordance with claim 4, in which the temperature of the surface layerof the tissue irradiated by the energy is controlled to be below 44° C.by circulating a fluid for cooling in a vicinity of said irradiatingunit.
 6. The method in accordance with claim 5, in which the temperatureof the fluid is below 37° C.
 7. The method in accordance with claim 5,in which the temperature of the fluid is 0° C. to 25° C.
 8. The methodin accordance with claim 5, in which the temperature of the fluid is 0°C. to 10° C.